The need for a positive angle fastener device for metal connectors used for connecting wood members exists in three separate areas; viz., (1) prevention of wood splitting due to wood shrinkage, (2) prevention of splitting of laminated wood members such as plywood glued laminated timbers (glulam and prefabricated wood joists (microlams), and (3) insertion of fasteners through a held member and a holding member which are joined by a special connector so that a plurality of fasteners will be in double shear.
The first two problem areas are fully discussed in Gilb U.S. Pat. No. 4,291,996 Sep. 29, 1981, and the third problem area is discussed in Gilb and Commins U.S. Pat. No. 4,480,941 granted Nov. 6, 1984.
Gilb U.S. Pat. No. 4,291,966, supra, taught the use of a slot-like opening in the face of the metal connector and then bending out a tab -like member formed from the displaced material. The Gilb tab-like device has been commercially very successful with thousands of hangers carrying the positive angle nailing device.
The Gilb tab-like device has several problems as set forth as follows: (1) the punching of a slot has a similar effect of punching a large opening in the metal which tends to weaken the metal; (2) the tab protruding from the metal tends to snag on other building materials prior to installation; (3) the protruding tab has invited installers who are not familiar with the purpose of the tab to forcibly bend the tab with a hammer or pair of pliers, thereby destroying the purpose of the tab; the tab is relatively easily bent during non-aligned hammering of the fastener during installation and (5) while the cost of forming the tab is minimal, yet it does require two stations; viz, a cutting station and a bending station thereby adding to the cost of manufacture.